Lipid foams are of particular interest to the consumer products industry, having the potential to provide new textures and sensory properties for food and nutrition products as well as in cosmetic products. In food products there is increasing concern about the amount of fat consumed in people's diet. Foaming lipids provides a method to maintain product volume whilst reducing the fat content.
The major difficulty in generating stable foam structures within lipid-based systems as compared to water-based systems lies in the lack of suitable surfactants for forming stable interfaces between air and lipid. Those surfactants which have been proposed may not be suitable for stabilizing edible foams due to toxicity or unpleasant taste. As a consequence, the most common approach for obtaining stable foams in a lipid-based matrix is by forming a rigid network in the bulk material, for example by forming a rigid network of crystals in a liquid lipid continuous phase or by rapidly cooling the lipid so as to solidify the bulk material. As well as affecting the texture in a way which may not always be desired, both of these approaches lead to constraints when processing the foam. Having a rigid network in the liquid lipid continuous phase affects the ability of the foam to be pumped, deposited, or mixed with other components without destroying the stabilizing network leading to coalescence of bubbles. A foam stabilized by solidifying the bulk is generally unstable before solidification and so can only be maintained as a foam for a short period and cannot be subject to substantial shear forces during processing.
Hence, there is a need in the industry to find better solutions to produce stable lipid foams, in particular edible lipid foams which taste good and are made from natural ingredients. An object of the present invention is to improve the state of the art and to provide an improved solution to overcome at least some of the inconveniences described above or at least to provide a useful alternative. Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field. As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to”. The object of the present invention is achieved by the subject matter of the independent claims. The dependent claims further develop the idea of the present invention.